IMAP and Zimbra 6

[Steve Hillman <hillman@sfu.ca>]

Hi folks,
  Last fall, I paid a visit to Zimbra's head office and had a chat with some of their developers. One thing that came to light is that in Zimbra 6, the IMAP engine has been redesigned: rather than requiring one IMAP thread per connection, there's now apparently a pool of threads to handle all of the connections, so theoretically at least, there's no limit on the number of IMAP connections a server can handle (or at least, it's sufficiently high). Unfortunately, I've been unable to track down the Zimbra Bugzilla ID that tracked this architecture change, so I can't read up on how it works, whether there are any tunables, etc

For those sites running Zimbra 6, have you noticed any change in IMAP behaviour? How many IMAP threads do you run with now? Anyone from Zimbra on this list care to share details - specifically, anything large sites should be aware of re:IMAP when upgrading to 6? What is now an optimal number of IMAP threads? We'd been continually bumping ours upwards to deal with all of our IMAP connections - we were up to 1000 per server (it by far dominated the list of threads in a Zimbra thread dump)

-- 
Steve Hillman                                IT Architect
hillman@sfu.ca                               IT Infrastructure
778-782-3960                                 Simon Fraser University